Improving the analytical performance of ion mobility spectrometer using a non-radioactive electron source
Improving the analytical performance of ion mobility spectrometer using a non-radioactive electron source
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DOI：
10.1007/s12127-016-0205-4
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发表时间：
2016-08
影响因子：
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通讯作者：
A. Heptner;Nico Angerstein-;T. Reinecke;E. Bunert;A. Kirk;Igor Niedzwiecki;S. Zimmermann
中科院分区：
文献类型：
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作者：
A. Heptner;Nico Angerstein-;T. Reinecke;E. Bunert;A. Kirk;Igor Niedzwiecki;S. Zimmermann
对于混合气体的电离，可以将几个电离源耦合到离子迁移率光谱仪。放射源，例如像63Ni和3H这样的贝塔辐射体，是最常用的电离源。然而，由于法律的限制，放射性电离源不适用于某些应用。非放射性替代方案是电晕放电电离源或光电离源。然而，使用电子枪可以通过简单地改变操作参数来调节离子产生速度、电离时间和复合时间，这可以用来提高离子迁移率光谱仪的分析性能。在这项工作中，我们展示了电离源参数变化对离子迁移率谱的影响。提高离子产生率，产生的离子数量增加，导致更高的信号强度，而噪声保持不变。因此，可以提高信噪比，从而获得更好的检测极限。在下一步中，保持离子产生速率不变，同时研究电离时间对离子迁移率谱的影响。结果表明，改变电离时间可以确定反应速率常数作为离子迁移率的附加信息。此外，我们还展示了通过结合使用较短的电离时间和较高的离子产生速率来防止歧视过程。从而提高了在甲苯存在下苯的检出限。此外，研究还表明，在低质子仿射离子已经复合的情况下，利用离子-离子复合可以在较高的复合次数下检测到质子亲和力最高的离子物种。因此，在定义的复合时间测量离子迁移率光谱允许抑制干扰的低质子仿生物质。
For the ionization of gas mixtures, several ionization sources can be coupled to an ion mobility spectrometer. Radioactive sources, e.g. beta radiators like63Ni and3H, are the most commonly used ionization sources. However, due to legal restrictions radioactive ionization sources are not applicable in certain applications. Non-radioactive alternatives are corona discharge ionization sources or photoionization sources. However, using an electron gun allows regulation of ion production rate, ionization time and recombination time by simply changing the operating parameters, which can be utilized to enhance the analytical performance of ion mobility spectrometers. In this work, the impact of an ionization source parameter variation on the ion mobility spectrum is demonstrated. Increasing the ion production rate, the amount of the generated ions increases leading to higher signal intensity while the noise remains constant. Thus, the signal to noise ratio can be increased, leading to better limits of detection. In a next step, the ion production rate is kept constant while the influence of ionization time on the ion mobility spectrum is investigated. It is shown, that varying the ionization time allows the determination of the reaction rate constants as additional information to the ion mobility. Furthermore, we show the prevention of discrimination processes by using short ionization times combined with an increased ion production rate. Thus, the limit of detection for benzene in presence of toluene is improved. Additionally, it is shown that using ion-ion recombination leads to the detection of the ion species with the highest proton affinity at higher recombination times while the low proton affine ions already recombined. Thus, the measurement of the ion mobility spectra at a defined recombination time allows a suppression of disturbing low proton affine substances.